Centrifugal analysers

ABSTRACT

A centrifugal analyser comprises a plurality of rotors each having a plurality of sample analysis chambers and, for each chamber, material receiving spaces from which material can be centrifuged into the associated chamber; and material loading means comprising a mechanism for accepting quantities of material from storage locations and which mechanism is movable selectively to loading locations associated with respective rotors for discharging the quantities of materials into the receiving spaces of a selected one of the rotors, whereby a loaded rotor can be rotated to centrifuge its contents whilst another rotor is being loaded.

United States Patent [1 1 Barber Sept. 2, 1975 4] CENTRIFUGAL ANALYSERS 3,722,790 3/1973 Natelson 233/26 75 I e t Bruce Will'am Ba be H rsham, 1 n of England I r r 0 Primary ExaminerGeorge H. Krlzmanlch Attorney, Agent, or Firm-Waters, Schwartz & Nissen [73] Assignee: M.S.E. Precision Manufacturers 7 Llmlted, Crawley, England [5 ABSTRACT [22] Flled: May 1973 A centrifugal analyser comprises a plurality of rotors [21] Appl. N0.: 363,050 each having a plurality of sample analysis chambers and, for each chamber, material receiving spaces from which material can be centrifuged into the associated [2?] (51 233l2g642b3/s2ig chamber; and material loading means comprising a mechanism for accepting quantities of material from [58] Field of Search 233/1 R, 14 R, 21, 22, t l d h h bl 233/23 R 24 25 26 23/259 sorage oca1ons an w 1c mec an 1sm1sn 1ova eselectwely to loadlng locatlons assoc1ated wlth respective rotors for discharging the quantities of materials [56] References C'ted into the receiving spaces of a selected one of the re- UNITED STATES PATENTS tors, whereby a loaded rotor can be rotated to centri- 3,081,158 3/1963 Winter 233/26 X fuge its contents whilst another rotor is being loaded. 3,192,968 7/1965 Baruch et a1. 23/259 x 3,193,358 7/1965 Baruch 233/26 x 9 Clams, 4 Drawmg Flgures PATENTEU SEP 2 i975 sum 2 j 3 PATENTEU 2 I975 sHmap g CENTRIFUGAL ANALYSERS BACKGROUND OF THE INVENTION This invention relates to centrifugal analysers and is particularly concerned with loading of such analysers. More specifically, the invention relates to centrifugal analysers of the kind which have a rotor containing a plurality of sample and analysis chambers normally formed as cuvettes, i.e., chambers with a radiation transmissible wall such that the contents of the chambers may be subjected to radiation, e.g., light, and the effect of that radiation on the contents sensed.

Conventionally, such a rotor has the cuvettes in an annular peripheral zone surrounding a space formed to receive a releasable loading disc containing for each cuvette a plurality of fluid'holding cavities into which measured quantities of materials are loaded by hand. When the loading disc has been charged in this manner, it is placed in the central space of the rotor prior to running the rotor up to speed to cause the contents of the fluid-holding cavities to be displaced by centrifugal force into the cuvettes. Following this, the rotor is stopped, the loading disc removed, the parts cleaned, and the loading disc re-loaded by hand in readiness for a further analysis. The manual intervention necessary does of course limit the rate at which analyses can be made.

It is an object of the present invention to provide an improved analyser requiring less manual intervention and enabling a greater rate of analyses to be made.

SUMMARY OF THE INVENTION According to the present invention, there is provided a centrifugal analyser comprising: two or more rotors each having a plurality of sample analysis chambers and, for each chamber, material receiving spaces from which material can be centrifuged into the associated chamber; and material loading means comprising a mechanism for accepting quantities of material from storage locations and which mechanism is movable selectively to loading locations associated with respective rotors for discharging the quantities of materials into the receiving spaces of a selected one of the rotors, whereby a loaded rotor can be rotated to centrifuge its contents whilst another rotor is being loaded.

It will be apparent that the material receiving spaces need no longer be formed in a separate loading disc and indeed they might be formed integrally with the material receiving chambers or cuvettes. In any case, it will be seen that there is no need for displacing the material receiving spaces relative to their associated chambers. This is achieved because loading can now be effected by the loading mechanism movable between storage locations and loading locations.

Moreover, because of the provision of two or more rotors, and the possibility of operating one whilst the others are loaded, one can achieve, in effect, continuous operation for relatively long periods, this simplifying operation and the analysis itself and also simplifying temperature control problems. One temperature system could suffice to control the temperature of the environment of the rotors and also of the storage locations. It also follows that an operator could have a greater degree of protection from possible infection in the case of biological analyses because a series of tests can be conducted without the need for frequent access to the analyser. Thus, the rotors may be contained in a temperature controlled compartment which could be purged with clean air at convenient intervals.

The loading mechanism may comprise two or more remotely controlled syringe units or their equivalent mounted on a rotatable structure rotatable about a point positioned at the intersection of straight lines drawn through the centres of the rotors. In this way, each material receiving space of any rotor can be loaded by indexing the rotor to be loaded to introduce its sets of material receiving spaces into the loading 10- cations. Storage locations may be provided for materials such as diluents and reagents and these locations may be stationary. In addition, a conveyor may be provided for passing a series of sample containers through a zone from which the loading means may withdraw the samples one at a time, such a zone being effectively another storage location. In the case envisaged such a zone will be positioned on the are described by the appropriate syringe unit of the loading mechanism.

For a better understanding. of the invention and to show how the same may be carried into effect, refer ence will now be made, by way of example, to the ac companying drawings, in which:

FIG. 1 is an axial cross-section of a rotor member;

FIG. 2 is a plan view of a portion of the rotor member of FIG. 1;

FIG. 3 is a block diagram indicating diagrammatically the arrangement of a centrifugal analyser; and

FIG. 4 is a diagram illustrating the optical system of the analyser of FIG. 4.

FIGS. 1 and 2 show in axial cross-section and plan a rotor member of transparent material, the member being denoted 1 and being shown in FIG. 1 in association with an annular and transparent top plate 2 which is clamped to the upper surface of the member 1.

The rotor member 1 contains a plurality, for example twenty-four, of radial series 3 of cavities, each series including two cavities 4 and 5 constituting material receiving spaces and a cavity 6 defined between the rotor member 1 and the top plate .2 and constituting a cu vette or sample analysers chamber. The radially outer end of each cuvette is connected to the periphery of the rotor member by a sinuous capillary channel 7 formed as a groove in the upper surface of the rotor member and closed by the top plate 2.. The channels 7 may be employed in the present analyser in the known manner for cuvette rotors.

In the present example, the :spaces 4 are intended to receive reagent and the spaces 5 are intended to receive both a sample and a diluent.

FIGS. 3 and 4 show a centrifugal analyser comprising a temperature controlled enclosure 8 containing two rotors 9 and 10, each having a rotor member 1 and top plate 2 as already described. Associated with both rotors is a loading mechanism comprising an arm 11 pivotally mounted about an axis 12 symmetrically disposed in relation to the rotors, the arm carrying dispensers 13 and 14 which may be, typically, syringes. FIG. 3 shows the loading position of the arm 11 for the rotor 9. In this position, the dispenser 13 overlies a space 4 in the rotor 9 and the dispenser 14 overlies the associated space 5. The arm 11 has a drive means 15 operable to drive the arm 11 to a corresponding load ing position for the rotor 10. Moreover, the rotors 9 and 10 have respective drive means 16 and 17 by which, in one mode, the rotors may be driven at a constant speed and, in another mode, the rotors may be indexed or stepped to place the sets of spaces 4 and 5 successively beneath the illustrated positions of the diluent and reagent dispensers 13 and 14. In practice, manual or automatic control means are provided to select the modes of operation of the drive means 16 and 17 such that one of the rotors is being driven to centrifuge its contents whilst the other is being indexed for loading.

The drive means of the arm 11 is also provided with manual or automatic control means whereby the arm 11 may be pivoted to the dotted line position illustrated at 18 in which the dispensers 13 and 14 overlie respective reservoirs 19 and 20, the reservoir 19 being a reservoir of diluent and the reservoir 20 being a reservoir of reagent.

The analyser furthermore comprises a conveyor 21 carrying a plurality of cups some of which are indicated at 22, these cups being intended to contain discrete quantities of sample. A portion of the conveyor is disposed in enclosure 8 and a portion is external thereof as seen in FIG. 3. The conveyor can be operated by any suitable conventional stepwise drive means to index the cups one by one through a location generally denoted 23 at which the arm 11 can also be stopped by the drive means 15 so that the dispenser 13 will overlie one of the cups 22 at the location 23.

FIG. 4 shows an optical system associated with the rotors, the system comprising a source 24 of monochromatic light, a photo detector 25, two pairs of prisms 26 and two mirrors 27. The mirrors 27 are rotatable through at least 180 about a vertical axis so that the optical system can be selectively driven, either automatically or manually, to pass light from the source 24 through the cuvettes of rotor 9 or rotor 10. As an alternative to having a common optical system, each rotor can have its own system so that there can be made accurate comparisons of simultaneous results received from experiments carried out in the different rotors.

In operation, the reservoirs l9 and 20 and the cups 22 will be charged with the appropriate materials and the temperature control system of the enclosure 8 will be operated to achieve a substantially steady temperature within the enclosure. The drive means 15 will then be operated to pivot the arm 11 to cause the dispenser 13 to be placed above a cup 22 at the location 23. The dispenser 13 will then be remotely actuated in conventional manner of remote operation of syringes to withdraw a predetermined amount of sample from the cup, following which the drive unit 15 will be actuated again to drive the arm 11 to the position 18. At this position, both dispensers are remotely actuated to withdraw measured amounts of diluent and reagent from the reservoirs l9 and 20. With both syringes appropriately charged in this manner, the drive means 15 is further operated to cause the arm 11 to move to the loading position in relation to one of the rotors, e.g., rotor 9. Further remote actuation of the dispensers 13 and 14 causes their contents to be discharged into a pair of receiving spaces 4 and 5. The rotor 9 is then indexed to bring the next pair of receiving spaces 4 and 5 to the loading location beneath the dispensers 13 and 14 so that the described operation of the arm 11 and the dispensers 13 and 14 can be repeated. This sequence of loading steps is repeated until a desired number of the sets of receiving spaces have been charged with the stored materials. The arm 11 may then be operated to commence the same loading procedure with the rotor 10 whilst the rotor 9 is run up to a constant speed to cause the materials to be centrifuged into the cuvettes 6, which then have their light transmission properties analysed by means of the optical system.

The operation of the analyser may be continued in this manner for an appreciable time by alternately loading and driving the rotors and to this end and if necessary a suitable rotor washing system may be incorporated to wash the rotors subsequent to each centrifuging operation.

I claim:

1. A centrifugal analyser comprising: two rotors each having a plurality of sample analysis chambers and, for each chamber, material receiving spaces from which material can be centrifuged into the associated chamber; and material loading means conprising a movable mechanism for accepting quantities of material, means for moving said mechanism from storage locations selectively to loading locations associated with respective rotors for discharging the quantities of materials into the receiving spaces of a selected one of the rotors, and means for driving said rotors such that a loaded rotor can be rotated to centrifuge its contents whilst another rotor is being loaded.

2. A centrifugal analyser as claimed in claim 1, wherein each rotor comprises a body having first recesses which define the material receiving spaces and further recesses defining said sample analysis chambers.

3. A centrifugal analyser as claimed in claim 1 and comprising means defining said storage locations at which there are containers, the material loading means including syringes for withdrawing material from said containers at said storage locations.

4. A centrifugal analyser as claimed in claim 3, comprising conveyor means for conveying containers through said storage locations.

5. A centrifugal analyser as claimed in claim 4, and comprising an enclosure for said rotors, said loading means and said storage location with means for maintaining a temperature controlled environment in said enclosure, said conveyor means being operable to convey the containers into and from said enclosure, whereby said containers may be loaded with material externally of said enclosure.

6. A centrifugal analyser as claimed in claim 1,com-

prising an enclosure enclosing said rotors, said material loading means and said storage location and means for maintaining a temperature controlled environment in said enclosure.

7. A centrifugal analyser as claimed in claim 1, wherein said movable mechanism for accepting quantities of material comprises at least two remotely controlled syringe units.

8. A centrifugal analyser as claimed in claim 1, wherein said movable mechanism comprises a rotatable structure rotatable about a region positioned at the intersection of straight lines extending through the axes of rotation of the rotors.

9. A centrifugal analyser as claimed in claim 1, wherein said means for driving said rotors comprises for each rotor drive means operable selectively to drive the rotor in a centrifuging mode and to drive the rotor in an indexing mode in which the material receiving spaces can be charged in succession at the associated loading location. 

1. A ceNtrifugal analyser comprising: two rotors each having a plurality of sample analysis chambers and, for each chamber, material receiving spaces from which material can be centrifuged into the associated chamber; and material loading means conprising a movable mechanism for accepting quantities of material, means for moving said mechanism from storage locations selectively to loading locations associated with respective rotors for discharging the quantities of materials into the receiving spaces of a selected one of the rotors, and means for driving said rotors such that a loaded rotor can be rotated to centrifuge its contents whilst another rotor is being loaded.
 2. A centrifugal analyser as claimed in claim 1, wherein each rotor comprises a body having first recesses which define the material receiving spaces and further recesses defining said sample analysis chambers.
 3. A centrifugal analyser as claimed in claim 1 and comprising means defining said storage locations at which there are containers, the material loading means including syringes for withdrawing material from said containers at said storage locations.
 4. A centrifugal analyser as claimed in claim 3, comprising conveyor means for conveying containers through said storage locations.
 5. A centrifugal analyser as claimed in claim 4, and comprising an enclosure for said rotors, said loading means and said storage location with means for maintaining a temperature controlled environment in said enclosure, said conveyor means being operable to convey the containers into and from said enclosure, whereby said containers may be loaded with material externally of said enclosure.
 6. A centrifugal analyser as claimed in claim 1 comprising an enclosure enclosing said rotors, said material loading means and said storage location and means for maintaining a temperature controlled environment in said enclosure.
 7. A centrifugal analyser as claimed in claim 1, wherein said movable mechanism for accepting quantities of material comprises at least two remotely controlled syringe units.
 8. A centrifugal analyser as claimed in claim 1, wherein said movable mechanism comprises a rotatable structure rotatable about a region positioned at the intersection of straight lines extending through the axes of rotation of the rotors.
 9. A centrifugal analyser as claimed in claim 1, wherein said means for driving said rotors comprises for each rotor drive means operable selectively to drive the rotor in a centrifuging mode and to drive the rotor in an indexing mode in which the material receiving spaces can be charged in succession at the associated loading location. 